Support recovery from C stack overflow on MS-Windows

* src/w32fns.c (w32_reset_stack_overflow_guard)
(stack_overflow_handler): New functions for handling C stack
overflow exceptions.
(my_exception_handler): Handle EXCEPTION_STACK_OVERFLOW exceptions
specially, and zero out except_addr if we do.
(globals_of_w32fns): Initialize dwMainThreadId in non-interactive
mode.
* src/sysdep.c [HAVE_STACK_OVERFLOW_HANDLING]: Add !WINDOWSNT to
the condition, as HAVE_STACK_OVERFLOW_HANDLING is now defined for
the MinGW build, but the code guarded by that is for Posix hosts.
* src/keyboard.c (command_loop) [WINDOWSNT]: Call
w32_reset_stack_overflow_guard.

* nt/inc/ms-w32.h (sigjmp_buf): New typedef.
(sigsetjmp): New macro.
(w32_reset_stack_overflow_guard): Declare the prototype.

* configure.ac (HAVE_STACK_OVERFLOW_HANDLING): Set to 1 for MinGW.

1 files changed, 3 insertions, 3 deletions

diff --git a/src/sysdep.c b/src/sysdep.c
index df3e573a6ea..25f111ad0ed 100644
--- a/src/sysdep.c
+++ b/src/sysdep.c
@@ -1612,7 +1612,7 @@ handle_arith_signal (int sig)
   xsignal0 (Qarith_error);
 }
 
-#ifdef HAVE_STACK_OVERFLOW_HANDLING
+#if defined HAVE_STACK_OVERFLOW_HANDLING && !defined WINDOWSNT
 
 /* Alternate stack used by SIGSEGV handler below.  */
 
@@ -1708,7 +1708,7 @@ init_sigsegv (void)
   return sigaction (SIGSEGV, &sa, NULL) < 0 ? 0 : 1;
 }
 
-#else /* not HAVE_STACK_OVERFLOW_HANDLING */
+#else /* not HAVE_STACK_OVERFLOW_HANDLING or WINDOWSNT */
 
 static bool
 init_sigsegv (void)
@@ -1716,7 +1716,7 @@ init_sigsegv (void)
   return 0;
 }
 
-#endif /* HAVE_STACK_OVERFLOW_HANDLING */
+#endif /* HAVE_STACK_OVERFLOW_HANDLING && !WINDOWSNT */
 
 static void
 deliver_arith_signal (int sig)